mrggkk: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/mrggkk - from package: abinit

You may install the required package with command apt-get install {package}

Error in other languages:
mrggkk: bevel nie gevind nie
mrggkk: comandă negăsită
mrggkk: comando não encontrado
mrggkk: commande introuvable
mrggkk: command not found
mrggkk: käsku ei ole
mrggkk: không tìm thấy lệnh
mrggkk: komanda nerasta
mrggkk: Kommando nicht gefunden.
mrggkk: kommandot finns inte
mrggkk: komut yok
mrggkk: nie znaleziono polecenia
mrggkk: níor aimsíodh an t-ordú
mrggkk: no se encontró la orden
mrggkk: no s'ha trobat l'ordre
mrggkk: opdracht niet gevonden
mrggkk: parancs nem található
mrggkk: perintah tidak ditemukan
mrggkk: príkaz nenájdený
mrggkk: příkaz nenalezen
mrggkk: команда не найдена
mrggkk: командата не е открита
mrggkk: 命令找不到
mrggkk: コマンドが見つかりません